PDPs are gaining more attention recently as flat display panels since they have more advantageous features than liquid crystal panels, including faster display time, wider viewing angle, ease of manufacturing large screens, and higher display quality realized by self-light emission. PDPs are being used in an expanding range of contexts, including as displays for public places and wide-screen display devices for domestic viewing.
In a PDP, gas discharge generates ultraviolet rays, and these ultraviolet rays excite the phosphors, which then emit visible light for color display. PDP driving systems can be generally classified into AC and DC types. The electric discharge system can be classified into two types: surface discharge and opposed discharge. The AC surface discharge type that has a 3-electrode structure is the mainstream type with respect to higher definition, larger screens, and easier manufacture. The PDP of the AC surface discharge type that has a 3-electrode structure is configured with multiple pairs of display electrodes aligned in parallel on one substrate, address electrodes disposed on the other substrate in such a way as to cross the display electrodes, a barrier rib, and a phosphor layer. Since the phosphor layer can be made relatively thick, this type of PDP is appropriate for color displays using phosphors.
The method of manufacturing PDPs includes the steps of forming panel components such as electrode, dielectric and phosphor one after another mainly using the step of forming a thick film on the surface of the front substrate and rear substrate by repeating printing, drying and firing; and overlaying and sealing the front substrate and rear substrate on which these panel components are formed. In the above steps, a firing device is used for drying and firing.
As for the firing device, a so-called roller-hearth kiln, fit for mass production, is employed. The roller-hearth kiln has its transportation means configured by aligning multiple rollers in the direction of transportation of the substrate. While firing the panel components formed on the front and rear substrates, the substrates are placed on a support substrate called a setter (this state is hereafter called the firing target) during transportation for firing to prevent damage to each substrate by the transportation means.
The quality of panel components greatly affects the display characteristic of PDP images. Accordingly, a firing process and firing device which prevent attachment or mixing of foreign particles to the panel components are demanded.
However, foreign particles are attached or mixed to the fired panel components when a conventional firing device is employed for firing. This causes, for example, variations in the resistance if the panel components are metal-wired, resulting in low yield for PDPs. One of the causes of foreign particles is abrasion powder generated by friction between the setter and roller when transporting the firing target on the rollers. This abrasion powder attaches mainly on the face of the setter contacting the roller. The setter transported in this condition scatters the abrasion powder in the entire firing device. Consequently, defects due to the abrasion powder occurs frequently.
The present invention is designed to solve this disadvantage, and aims to offer a method of manufacturing PDPs and a firing device employed in the manufacture that reduce attachment or mixing of abrasion powder generated by friction between the roller and setter to the panel components.